CN205139762U - Linear difference hall voltage generator of tiling structure - Google Patents

Abstract

The utility model relates to a linear differential Hall voltage generator with a tiled structure, which includes a first Hall semiconductor chip and a second Hall semiconductor chip that are tiled on a substrate and are adjacent to each other, the specifications of the two semiconductor chips and The electrical properties are the same, the first Hall semiconductor chip and the second Hall semiconductor chip are connected in reverse series in the constant current source power supply circuit, the voltage output terminal of the first Hall semiconductor chip is connected to the first differential amplifier, and the second Hall semiconductor chip The voltage output terminal of the semiconductor chip is connected to the second differential amplifier, and the output terminal of the first differential amplifier and the output terminal of the second differential amplifier are connected to the third differential amplifier. The utility model has the advantages of simple circuit structure, convenient use, stable system and high measurement precision.

Description

A Linear Differential Hall Voltage Generator with Tiled Structure

technical field

The utility model relates to the field of Hall sensors, in particular to a flat structure linear differential Hall voltage generator.

Background technique

Current sensors are generally designed with ferromagnets and linear Hall elements. Because temperature changes affect the voltage output of Hall elements, current sensors require complex temperature compensation and linearity correction. There are many compensation measures and linear correction methods, which can be roughly divided into circuit compensation, software compensation and multi-sensor fusion technology compensation. Although these technical methods have improved the stability and measurement accuracy of the sensor to a certain extent, the implementation methods are complicated, the cost is high, and the precision is low, and the self-compensation and correction of the Hall elements are not fully utilized.

Circuit compensation technology generally uses temperature sensitive devices to sample the ambient temperature, and performs temperature compensation and linear correction through signal processing circuits. For different types of semiconductor devices, it is difficult to ensure the consistency of temperature characteristics, which may cause undercompensation or overcompensation. Although the measurement accuracy of the sensor is improved, it also introduces interference signals that have nothing to do with the measured current.

The software compensation method is to perform temperature compensation and linearity correction on the sensor through the application software, which saves the circuit compensation, but the software compensation is targeted and requires high consistency of the current sensor, so it is difficult to ensure uniformity. The sensor itself has no compensation function and is not universal.

The multi-sensor fusion technology compensation method is more complicated. The current sensor and temperature sensor work together to obtain current and temperature information, and the application software performs numerical fusion to correct the measurement data in real time to obtain compensation; it also has the disadvantages of software compensation.

In summary, these compensation methods are complex and difficult to guarantee measurement accuracy. The document "Complementary combination of linear Hall elements and its differential application, automatic instrumentation 2010.04" proposed a differential application technology for linear Hall elements, which can effectively suppress To avoid temperature drift and common mode interference, the patent CN200920028862.X uses this technology to design a differential Hall component, which simplifies the compensation measures of the current sensor; the inventor also uses this component to design the patent CN200920239770.6 differential Hall current sensor, which significantly improves the performance of the sensor. The analysis found that this kind of component adopts an overlapping structure, and the size of the component is the thickness of two Hall elements. When it is used in the design of a current sensor, it will inevitably cause the air gap of the ferromagnet to increase, resulting in an increase in the reluctance and reducing the current sensor. sensitivity. Therefore, the utility model designs a linear differential Hall voltage generator with a tiled structure, which can not only suppress temperature drift and common-mode interference from the signal source, but also reduce the air gap of the ferromagnet, which is beneficial to improve the current sensor. Linearity, sensitivity, and measurement accuracy all have important application values for simplifying compensation and correction measures, optimizing design, and reducing costs.

Utility model content

The technical problem to be solved by the utility model is to provide a tiled linear differential Hall voltage generator with simple circuit structure, convenient use, stable system and high measurement accuracy.

In order to solve the above-mentioned technical problems, the structural feature of the tiled linear differential Hall voltage generator of the present invention is to include a first Hall semiconductor chip and a second Hall semiconductor chip tiled on the substrate and adjacent to each other. The specifications and electrical properties of the two semiconductor chips are the same, the first Hall semiconductor chip and the second Hall semiconductor chip are connected in reverse series in the constant current source power supply circuit, and the voltage output terminal of the first Hall semiconductor chip is connected to the first differential An amplifier, the voltage output end of the second Hall semiconductor chip is connected to the second differential amplifier, and the output end of the first differential amplifier and the output end of the second differential amplifier are connected to the third differential amplifier.

The housing of the voltage generator is provided with a positive power supply terminal connected to the positive power supply, a negative power supply terminal connected to the negative power supply, a ground terminal and an output terminal of the voltage generator; The ground is formed, the three differential amplifiers are all driven by the positive power supply and the negative power supply, and the output terminal of the voltage generator is drawn out from the output terminal of the third differential amplifier.

The two semiconductor sheets are both rectangular sheets, the two rectangular sheets are located on the same plane and have the same size and thickness, and the distance between the edges of the two rectangular sheets is ≤1mm.

The beneficial effects of the utility model are: two Hall semiconductor chips are connected in reverse series, their working currents are the same, and their directions are opposite, the output polarities of the two Hall voltage generators formed by them are opposite, and the output voltage has the characteristic of differential mode signal , after amplification, the signal voltage is output in the form of voltage difference, which has differential characteristics. Since the output of the voltage generator has differential output characteristics, the voltage generator itself can suppress common-mode signals and temperature drift, and has the characteristics of self-compensation and linear correction, which improves the output linearity and ensures the stability and measurement accuracy of the signal processing system. . At the same time, the two semiconductor chips are tiled on the same plane, and the thickness is the same as that of the existing single-chip Hall sensing unit. The voltage generator adopts a four-pin structure, which is convenient for modification and is more suitable for current sensors. use.

Description of drawings

Below in conjunction with accompanying drawing and specific embodiment the utility model is described in further detail:

Fig. 1 is the circuit structure schematic diagram of the present utility model;

Fig. 2 is a schematic diagram of the housing package structure of the present invention.

detailed description

Referring to the accompanying drawings, the tiled linear differential Hall voltage generator includes a first Hall semiconductor chip 11 and a second Hall semiconductor chip 12 that are tiled on the substrate and are adjacent to each other. The specifications and electrical characteristics of the two semiconductor chips are as follows: The properties are the same. The first Hall semiconductor chip 11 and the second Hall semiconductor chip 12 are connected in reverse series in the constant current source power supply circuit, the voltage output end of the first Hall semiconductor chip 11 is connected to the first differential amplifier 14, and the second Hall semiconductor chip The voltage output terminal of the chip 12 is connected to the second differential amplifier 15 , and the output terminals of the first differential amplifier 14 and the output terminal of the second differential amplifier 15 are connected to the third differential amplifier 16 . The housing of the voltage generator is provided with a positive power supply terminal connected to the positive power supply VCC, a negative power supply terminal connected to the negative power supply VSS, a ground terminal GND and an output terminal of the voltage generator. The constant current source power supply circuit is formed by the positive power supply VCC passing through the constant current source 13 and then grounded. The three differential amplifiers are all driven by the positive power supply and the negative power supply. The output terminal of the voltage generator is drawn from the output terminal of the third differential amplifier.

In the utility model, the two semiconductor sheets are rectangular sheets, and the two rectangular sheets are located on the same plane and have the same size and thickness. At the same time, the center distance between the two rectangular sheets is minimized, and the edge distance is ≤1mm. The two semiconductor chips are tiled on the same plane, and the thickness is the same as that of the existing single-chip Hall sensing unit. The voltage generator adopts a four-pin structure, which is convenient for modification and is more suitable for use on current sensors.

The two Hall semiconductor chips are connected in reverse series, the working current is the same, and the direction is opposite, the output polarity of the two Hall voltage generators formed by it is opposite, the output voltage has the characteristics of differential mode signal, and the difference is calculated by voltage after amplification The way to output the signal voltage has differential characteristics. Since the output of the voltage generator has differential output characteristics, the voltage generator itself can suppress common-mode signals and temperature drift, and has the characteristics of self-compensation and linear correction, which improves the output linearity and ensures the stability and measurement accuracy of the signal processing system. .

The left half of Fig. 1 is the principle diagram of the Hall voltage generator in the utility model. In the figure, the electrical properties of the two semiconductor chips 11 and 12 are the same, and the size parameters are the same; 13 is a constant current source, and VCC is a positive power supply; B is the magnetic induction acting on 11 and 12, and ⊙ represents the direction; if the flow passes through 11 and 12 The operating current of 1 is I, obviously the currents of 11 and 12 are equal in size and opposite in direction; the spatial structures of 11 and 12 are tiled and symmetrically distributed on the same plane, and the distance between them is small enough, which can be regarded as the same magnetic induction intensity acting on them; The Hall voltage output by 11 is U1, and the Hall voltage output by 12 is U2.

The right half in Fig. 1 is the schematic diagram of the differential amplifier in the utility model. In the figure, A1, A2, and A3 represent operational amplifiers, and R1-R12 are resistors, wherein A1, R1, R2, R3, and R4 constitute the first differential amplifier 14, which is connected to the output of the first Hall semiconductor chip. The input voltage is U1, the output The voltage is U3; A2 and R5, R6, R7, R8 form the second differential amplifier 15, which is connected to the output of the second Hall semiconductor chip, the input voltage is U2, and the output voltage is U4; the parameters of these two differential amplifiers are the same, set The gain of the two is K1; A3 and R9, R10, R11, R12 constitute the third differential amplifier 16, its input is connected to A1, A2 output respectively, the input voltage is U3, U4, the output voltage is U0, its gain is K2; VCC is a positive power supply, and VSS is a negative power supply.

Fig. 2 is the package schematic diagram of the present utility model, among the figure pin 1 is working positive power supply VCC, pin 2 is output voltage UO, pin 3 is power ground GND, pin 4 is negative power supply VSS; Sensor thickness after packaging Like the thickness of a Hall element.

The effect brought by the utility model is quantitatively analyzed below, and the voltage output characteristics of the two Hall semiconductor chips are analyzed first. The voltage generator is composed of two Hall semiconductor chips. The Hall semiconductor chip is referred to as Hall voltage generator or Hall element, and its output voltage is proportional to the magnetic induction B. Assuming that the parameters of the two Hall elements are the same, their operating currents are equal in size and opposite in direction, and the Hall voltage coefficient of the Hall element is KH. According to the Hall effect, the output characteristics of the two Hall elements can be expressed as:

U ₁ ＝+K _H B(1)

U ₂ ＝-K _H B(2)

When the temperature changes, the Hall element will produce a temperature drift. Let the temperature drift voltage caused by the temperature be Ut, and the formula (1) and formula (2) can be modified as:

U ₁ =U _t +K _H B(3)

U ₂ ＝U _t -K _H B(4)

Equations (3) and (4) show that if two Hall elements of the same nature pass through the same operating current with the same magnitude and opposite direction, when they are in the same magnetic field, the polarity of the temperature drift voltage does not change with the magnetic field, and the Hall voltage The polarities are opposite, that is, the temperature drift voltage Ut belongs to the common mode signal, and the signal voltage KHB belongs to the differential mode signal.

The output characteristic of the utility model is analyzed below. Referring to Figure 1, the differential amplifier composed of A1 is used to amplify U1, and the differential amplifier composed of A2 is used to amplify U2. Assuming that the gains of A1 and A2 are both K1, according to Equation 3 and Equation 4, the output voltages of A1 and A2 are respectively :

U ₃ =K ₁ U _t +K ₁ K _H B(5)

U ₄ ＝K ₁ U _t -K ₁ K _H B(6)

The output of A1 and A2 is differentially amplified by the differential amplifier formed by A3, and the gain of A3 is set to K2, according to formula (5) and formula (6), the output voltage is U _O =U ₃ -U ₄ .

U _O ＝2K ₁ K ₂ K _H B(7)

Because K1, K2, and KH are all constants, let K=2K ₁ K ₂ K _H , then Equation 7 can be rewritten as

U _O =KB(8)

It can be seen from formula (7) that the output of the voltage generator suppresses the temperature drift voltage Ut, and the output voltage after differential amplification of the dual Hall element is twice the output voltage of the single Hall element, doubling the measurement sensitivity; 8) It can be seen that the output voltage of the voltage generator is only related to the magnetic induction intensity, UO is proportional to B, and has nothing to do with the temperature drift, which significantly improves the linearity and effectively suppresses the influence of temperature drift on the sensor.

For the package structure of the present invention, referring to FIG. 2 , the Hall voltage generator and the differential amplifier circuit in a tiled structure are packaged in the same package case. Among them, pin 1 is the working positive power supply VCC, pin 2 is the output voltage UO, pin 3 is the power ground GND, and pin 4 is the negative power supply VSS. Since the Hall element adopts a tiled structure, the thickness of the encapsulated voltage generator is the same as that of the existing single Hall element.

The utility model optimizes the output characteristics of the voltage generator, and has the characteristics of low price, simplicity and practicality. The differential amplifier output has the advantages of suppressing common-mode interference, reducing temperature drift, and increasing signal amplitude. The voltage generator has the characteristics of temperature self-compensation and linear correction, and temperature compensation measures can be omitted. It is useful for simplifying circuit design, improving measurement systems and The stability and measurement accuracy of the signal processing system have practical significance; the packaging thickness of the voltage generator is reduced, which is more suitable for practical applications.

To sum up, the utility model is not limited to the above specific embodiments. Those skilled in the art can make several changes and modifications without departing from the spirit and scope of the present utility model. The protection scope of the utility model should be based on the claims of the utility model.

Claims (3)

1. the linear differential Hall voltage generator of a tile arrangement, it is characterized in that comprising and be laid on substrate and the first Hall semiconductor chip (11) be close to and the second Hall semiconductor chip (12), the specification of two semiconductor chips is all identical with electrical properties, first Hall semiconductor chip (11) and the second Hall semiconductor chip (12) are oppositely serially connected in constant current source power supply loop, the voltage output end of the first Hall semiconductor chip (11) connects the first differential amplifier (14), the voltage output end of the second Hall semiconductor chip (12) connects the second differential amplifier (15), the output terminal of the first differential amplifier (14) and the output terminal of the second differential amplifier (15) are connected to the 3rd differential amplifier (16).

2. the linear differential Hall voltage generator of tile arrangement as claimed in claim 1, is characterized in that voltage generator housing being provided with the positive power terminal be connected with positive supply (VCC), the negative power source terminal be connected with negative supply (VSS), ground terminal (GND) and voltage generator lead-out terminal; Described constant current source power supply loop is formed by positive supply (VCC) ground connection after constant current source (13), and three differential amplifiers drive by positive supply and negative supply, and voltage generator lead-out terminal is drawn by the output terminal of the 3rd differential amplifier.

3. the linear differential Hall voltage generator of tile arrangement as claimed in claim 1 or 2, it is characterized in that two semiconductor chips are rectangular sheet, two rectangular sheets are positioned at same plane and size is identical with thickness, the spacing≤1mm at two rectangular sheet edges.